Process for field reconstruction of well drilling stabilizers



Oct. 24, 1%? BASS, JR 3348,25

PROCESS FOR FIELD RECONSTRUCTION OF WELL DRILLING STABILIZERS Filed Oct. 21, 1965 2 Sheets-Sheet 1 Aim/"nay? Get. 24, 1%? s. L. BASS, JR 334,295

PROCESS FOR FIELD RECONSTRUCTION Of WELL DRILLING STABILIZERS Filed Oct. 21, 1965 2 Sheets-Sheet 2 56M L 3.455; n[a

United States Patent 3,348,295 PROCESS FOR FIELD RECONSTRUCTION OF WELL DRILLING STABILIZERS Sam L. Bass, Jr., 183 Eckhart Drive, New'lberia, La. 70560 Filed Oct. 21, 1965, Ser. No. 499,554 2 Claims. (Cl. 29401) ABSTRACT OF THE DISCLOSURE A method for field reconstruction of well drilling stabilizers in which the worn blades are removed, replacements are welded on the stabilizer, then the welded assembly is heated to a temperature at the locus of the blades of from about 700 F. to 1000 F. and slowly cooled to ambient temperature.

In deep drilling, as for petroleum or other fluid minerals, it is well known that drill stems are used totaling several thousand feet in length. At the terminus of the stem is the cutting head or bit. The bore actually out by the bit is appreciably larger than the diameter of the stern. It is therefore necessary to provide a device to maintain, generally, the axial alignment of the stem in the zone above the bit, as well as throughout the length of the stem, so that flexing and whipping of the stem does not occur.

Devices to achieve the above-described alignment func tion are termed stabilizers and consist in part of a relatively short (as compared with a section of drill stern) segment of round stock, of the same diameter as the drill stem. Attached rigidly to this segment, termed the body of the stabilizer, are several blade elements. The blade elements can be straight bar segments of rectangular cross section, three being welded to the body at equally spaced positions around the body at about the middle of its length. Preferably, the blade elements are somewhat similar to short segments of a square thread of a screw, the length being such that only a fraction of the circumference of the body is engaged.

As mentioned, severalusually threeblades are provided for each stabilizer, and are equally spaced around the circumference of the body, and are all approximately equidistant from each end. The body is end fitted with male and female threading means for connection to contiguous segments of the drilling assembly.

It will be understood that the above described blades project sufiiciently to approximately engage the walls of the Well bore, thereby preventing whipping of the drill stem. Stabilizers are placed at intervals through the entire drill stem.

Because of the highly abrasive service conditions to which the blades are subjected, they are frequently provided with an outside hardened surface such as a carbide or various hard alloy materials. Nevertheless, field replace ment of stabilizers is frequently necessary, as the blades become worn down to the point at which the stabilizer is no longer effective. When the well site is near a supply center, new stabilizers are readily provided. However, when wells are in remote areas, or on off-shore drilling platforms, supply of replacement stabilizers is diflicult and expensive.

An object of the present invention is to provide a process whereby stabilizers can be rebuilt in the field with considerable savings in effort and expense, and greatly improved convenience. An additional object is to provide apparatus for carrying out field reconstruction of stabilizers.

According to the present invention, a preformed blade or set of blades is provided having a configuration adapted for snug engagement with a stabilizer body. The process of "ice applying the blades to a worn stabilizer includes first, removing worn blades, then tack welding the replacement blades in place. The thus formed assembly is then uniformly heated to an elevated temperature of, usually, 700 F. to 800 F., and, While the assembly is hot, the welding is completed. A drop in temperature of perhaps several hundred degrees is experienced during the welding. Upon completion of the welding, the stabilizer is reheated in order to stress relieve to about 1000 F., and then allowed to cool slowly to ambient temperature.

In an alternative procedure, the blades are entirely welded before the heating, but this is a less preferred method.

' The details of the invention and of the best mode of utilizing it will be apparent from the detailed description hereafter given, in conjunction with the figures, wherein:

FIG. 1 is one view of a preformed blade of the invention,

FIG. 2 is a view of a completed stabilizer showing blades in position, and

FIG. 3 is a view of a novel furnace or heater for carrying out the process of the invention.

Referring to FIG. 1, a typical blade 11 of the invention is shown. The blade resembles a short segment of extended helix and has a generally rectangular cross section, typical dimensions being 1" x 1%". The inner surface is adapted to fit snugly against a cylindrical stabilizer body. The ends of a blade consist of a face 13, 14 leading in an inclined manner from the outer face 15 to the inner face. As previously mentioned, the outer face 15 is hard surfaced, for example with a manganese bearing alloy applied by welding. In preferred embodiments, a leading or end face 13 is also hard surfaced.

A completed stabilizer body is shown in part by FIG. 2. The three blades 21, 22, 23 are shown attached to the body 24 of the stabilizer. Typical length proportions are about one-fourth or three-eighths of the stabilizer body occupied by the blades. Thus in a four foot long stabilizer, the blade section is about 1 /2 feet long. Secure attachment is provided by weld metal at the lines 25 of juncture of the inner face boundary with the stabilizer body, except for the trailing edges 21c, 22c, 230.

The improved process of reconstruction will now be described, in conjunction with FIG. 3, a pictorial view of the improved furnace provided for the process.

Referring to FIG. 3, a furnace structure is shown which not only provides for uniform heating of the stabilizer body, and the final reconstructed stabilizer, in the several stages of the process, but also serves as a work positioner during the reconstruction process.

The furnace comprises a bottom segment and a top or lid segment 40. The bottom segment in this embodiment is in the form of one-half a cylinder or drum, having end plates 31, 32. Semi-circular recesses 31a, 32a are cut from the top of each end plate and are sized to loosely accommodate one-half the thickness of a stabilizer body. Pairs of rotatable support wheels 33a, 33b, 34a, 34b are also mounted at each end plate and are positioned to support a stabilizer body 50 without allowing engagement of the stabilizer body with the recesses.

The top segment is a matching part container adapted to serve as a lid or closure for the furnace. It is preferably hinged to the bottom segment 30. Recesses 41a, 42a in the end plates 41, 42 are provided to match with the recesses 31a, 32a in the end plates of the lower segment.

Heat is provided to the furnace by fuel, preferably gaseous, introduced through burners arranged in rows, 35, 36 and feeding through the lower segment 30. When the upper segment 40 is closed, it forms a closed heating 0 chamber for the portion of the stabilizer within the furnace, so that uniform and rapid heating is provided.

In carrying out the process, worn or distorted blades are first removed from the stabilizer body, by a suitable burning torch. The body surfaces are then dressed or smoothed by filing or grinding. The stabilizer body is then mounted on the rollers 33a, 33b, 34a and 34b of the furnace, and the replacement blades are positioned in place and tack-welded. The lid 40 of the furnace is closed and heating is started and continued until the stabilizer body within the furnace reaches a temperature of from 700 F. to 1000 F. Heating 'is discontinued, the furnace top 40 is lifted, and the welding is then completed.

Normally, the welding is carried'out along the two long edges of a blade and the short, leading, edge. By leading is meant the edge lowermost in the well when the stabilizer is in use.

Upon completion of the welding, the heating is again discontinued and the reconstructed stabilizer is allowed to cool slowly to ambient temperature and is then ready for use.

It will be understood that the above process is fully applicable to the reconstruction of stabilizers having 20 removing worn blades from a stabilizer, welding replacements on the stabilizer,

heating said welded assembly to a temperature at the locus of the blades of from about 700 F. to 1000 F.

and slowly cooling to ambient temperature.

2. The process of claim 1 further defined, in that the Welding includes the steps of (a) tackwelding the blades in positon, then (b) heating the assembly to an elevated temperature,

and

(c) then completing the welding of the blades along at least the two long edges adjacent to the stabilizer body and the leading edge.

References Cited UNITED STATES PATENTS 2,775,811 1/1957 Wilson 29-401 3,103,065 9/ 1963 Rectenwald 29497 X 3,227,008 1/ 1966 Celovsky 76101 I OHN F. CAMPBELL, Primary Examiner.

THOMAS H. EAGER, JOHN J. CAMBY, Examiners. 

1. A PROCESS FOR FIELD RECONSTRUCTION OF WELL DRILLING STABILIZERS, COMPRISING REMOVING WORN BLADES FROM A STABLILIZERS, WELDING REPLACEMENT ON THE STABILIZER, 